Pilot Safety Valve

Brief Introduction

The product has pilot operation and double nature seal, whose precision is high and reliability is good. The product’s pop is obvious, relief capability is strong, and after relief, the product can recover the air bubble level seal. The design of product is unique, and at the leading position in domestic. It’s degree of standardization and generalization is high. The product is suitable for natural gas pipeline, boiler, container.
Obtained state stress novelty in 2001 years, the national torch plan project in 2003 years and gained state technology innovation fund item in 2005 years. 
Application outstanding achievement: Transport the natural gas from the west to the east project, China-Australia collaborate Guangdong LNG item, Xinjiang Tarim gas field, China sea oil Orient –Yangpu-Haikou gas pipeline project, Southwest gas field branch, etc.

Principle of operation

The product main valve and pilot valve adopt seamless tube put through, by the pilot valve came sensing by control pressure signal combine Control the main valve master's start and stop. The movement course is: while the main valve front pressure under the conditioning pressure, the pilot valve setting sprung should push the needle to valve base seal, gaseous medium from pilot valve to ingress main valve needle's top antrum lead the needle downward shift adherence valve base，Both pilot valve and main valve get off to leak less inactive state. And when the valve front pressure reach or tower the conditioning pressure，the media pressure overcome the set-pressure，sprung should push pilot valve's needle up shift， the pilot valve lifting surface area from needle area translate into plunger area，the lifting surface area eke climbing power aggrandizement， the pilot valve unlock.The main valve bush top antrum gasses from the pilot valve export vent, the main valve unclose, the media readiness let piston stroke till max position. While the media pressure let to definite pressure, the pressure of through plunger damping hole brought fluctuate area pressure difference equilibrium, the “start-stop” pressure difference by plunger fluctuate area pressure difference balanced realization, when the front pressure recur working pressure hereinafter, under the action of on the small side spring force, the needle downward shift realize its seal. The pilot valve shut, then the main valve shut too. 

Structure, performance point: 
The main valve adopts self-tight structure, and the pilot valve adopts labyrinth damping piston structure. The product design is ingenious, principle is correct. It’s structure is novel and compact. Technical specification reaches and surpasses the national stardard. The product’s precision is high, and discharge capability is strong. In the extremely scope above set pressure, the product can decompress and discharge, which resets correctly, seals reliably, works quite stably.
The main valve and pilot valve adopt hard soft seal, which bears wash. The valve’s service life is long.
On the condition of high pressure differential, the product can meet the usage requirement of sour gas and high sour gas. 

It has stable technical performance and air bubble seal, and its energe conservation is remarkable.

Main advantages：
1. The pilot valve adopts labyrinth damping piston structure, it lets safety valve immediate emissions when pressure to high, implementation over pressure △Po＜3%Ps, reached the international advanced level. Compared with the general safety valve over pressure △Po≤5%～10%Ps, accuracy in emissions achieved a major breakthrough, to meet the safety valve function of the ideal state. 
2. Main valve adopts hard soft seal, when piston bottom-end open instantaneous forms cutting expenditure side and spool completely separate from the sealing surface, avoid the sealing surface washed by the medium. Over pressure immediate emissions, avoid a safety valve in the pressure range over large, pressure differential emissions sealed a long period of erosion and the vice thus creating the phenomenon of cavitations damage vice sealed, so life time become longer. 

3. The safety valve designs guide style because of operating principle and structure characteristic innovative, it being able to satisfy heavy pressure (PN25.0MPa), big diameter (DN200) gas medium leaks regular duty of pressure and easy maintenance.

Technology index:

Notice：
ANSI
1. The structure length of comply with standard of API 526 “Flanged Steel Pressure Relief Valve”.If user has vary ask，please indicate in order time，our company should special design for satisfaction.
2.Safety valve outlet diameter is bigger than the inlet diameter for one grade or more，the inlet/outlet flange connecting dimensions of comply with standard of ANSI B16.5.
3.The discharging area of safety valve according to calculate ascertain bled mete of working condition required, with standard of API526 choice corresponding rule discharging ora code.
GB
1. The inlet flange pressure class is bigger than the outlet flange pressure class for one grade or more, The outlet diameter is bigger than the inlet diameter for one grade or more.

Performance & Dimensions